A critical vulnerability in popular software development collaboration products by Atlassian allows attackers to compromise servers.

The vulnerability affects Atlassian Confluence, a wiki-like collaboration platform for software development teams; Bamboo, a software build and testing platform; FishEye, a code-tracking system for centralizing different repositories; and Crucible, a collaborative peer code review framework.

Attackers can exploit the vulnerability to execute arbitrary Java code on systems that use the affected frameworks, as long as they can access their Web interfaces, the company said in security advisories published Wednesday. To exploit Confluence, the attacker also needs to have access to an account on the platform.

If the affected products are not directly accessible from the Internet or other untrusted networks, the risk of compromise is reduced because the attacker would first have to gain access to the same network as the servers hosting them. Companies whose installations need to be accessible from the Internet can block requests in their firewalls that match specific regular expressions released by Atlassian.